The project “Alcohol Detection and Engine Locking System” is designed to prevent drunk driving and ensure road safety by detecting the presence of alcohol in a driver’s breath and automatically disabling the vehicle’s ignition system. The system uses an alcohol sensor (MQ-3) that continuously monitors the driver’s breath. When the sensor detects alcohol concentration above a predefined threshold, it sends a signal to the microcontroller, which immediately activates the engine locking mechanism, preventing the vehicle from starting. A buzzer is triggered to alert the driver or surrounding individuals about the detected alcohol presence. The system operates using a regulated power supply, which provides stable DC voltage to all electronic components, ensuring reliable operation without the risk of power discharge or fluctuation. This design helps maintain continuous monitoring capability even during long operation periods. The proposed system promotes responsible driving behavior, reduces accidents caused by drunk driving, and can be easily integrated into modern vehicles as a low-cost safety enhancement.  

Objectives:

 To measure and compare voltage at two points in the power line using a potential divider circuit.

 To detect voltage imbalance caused by unauthorized tapping or theft.

 To activate a buzzer alarm when theft is detected.

 To protect the electrical distribution system and reduce power losses.

 To demonstrate a simple and cost-effective theft detection method for educational and industrial applications.    

The Major Building blocks of this project are:  

• Regulated power supply.
• PIC micro controller.
• BO Motor along with Relay.
• Buzzer.
• Alcohol Sensor.

  Software’s used:  

1. Embedded C programming.
2. PIC C compiler programmer for dumping code into Micro controller.
3. Express SCH for Circuit design.

   

Regulated Power Supply:  

               

  Block diagram:  

   

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